Means and method for protecting a windshield from cracks

ABSTRACT

A structure and method for protecting a windshield from damage and therefore the development of cracks due to stone or other impact on windshields around the peripheral area. An impact resistant barrier is placed around the periphery of the windshield. The barrier is preferably a clear polymeric film, but could be opaque, rubber, plastic or metal. The barrier is placed on the glass surface and in contact adjacent to the windshield molding. The width of the barrier is selected to eliminate the higher incidence of damage to the peripheral area. The barrier can be combined with a sunlight blocking ingredient to reduce degeneration of urethane which is used in mounting the windshield to the vehicle. A kit can be assembled with the elements needed to place the barrier on a windshield.

RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.08/834,717 filed on Apr. 1, 1997, now U.S. Pat. No. 5,860,689 which is acontinuation-in-part of application Ser. No. 08/646,036 filed on May 7,1996, now U.S. Pat. No. 5,653,497, the content of each of which isincorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to means and methods for preventing and protectingautomobile windshields from damage caused by impacts from flyingobjects. In particular the invention relates to a barrier placed aroundthe periphery of the windshield to absorb the impact from objects andthereby prevent damage.

BACKGROUND

Damage to windshields caused by debris or other impacts has long been aproblem. Many patents have issued and a substantial business thrivesrespecting the repair of such damage. For a long time it was believedthat long cracks, that is cracks over six inches in length could not berepaired. However, shorter cracks referred to as stone damage wererepairable. Later through significant developments in the field itbecame possible to repair long cracks. Patents which relate to therepair of long cracks in windshields are U.S. Pat. No. 5,116,441, U.S.Pat. No. 5,425,827, U.S. Pat. No. 5,429,692, U.S. Pat. application Ser.No. 08/436,155, U.S. Pat. application Ser. No. 08/436,591 and U.S. Pat.application Ser. No. 08/459,039.

Also, there is a thriving business in the replacement of crackedwindshields which either cannot be repaired or which are believed to beunrepairable. In fact replacement is vastly more common than repair.

Despite these thriving businesses damage to windshields present costs tothe consumer because of the cost of the repair or replacement. Wheninsurance covers the damage then there is an insurance company losswhich is passed on to consumers through their premiums. Also tons ofunrecycled waste are created year after year.

Impacts which cause damage near the glass edge nearly always result inan edge crack, that is a crack running through the impact point to theedge of the glass. These cracks are also nearly always long cracks, thatis over 6 inches in length. By contrast impacts in the middle area ofthe windshield quite often result only in the limited damage known aschips or stone damage, that is a bullseye, a star break or a combinationand absent any long crack. Thus the problem of windshield damage in theperipheral area is considerably greater than in the middle. Long cracks,especially edge cracks, demand attention soon after cracking and mostend up being replaced.

Windshields are installed with a rubber or plastic and in some casesmetal, molding. Presently, most moldings are 1-2 centimeters wide, about50% of the molding width extending over the glass. The maximum knownmolding width covers 2 cm of the windshield glass.

SUMMARY OF THE INVENTION

The present invention provides a means and method for protecting awindshield from damage and therefore the development of cracks due tostone or other impact on windshields around the peripheral area.According to the invention, an impact resistant barrier is placed aroundthe periphery of the windshield. The barrier is preferably a clearpolymeric film, but could be opaque rubber, plastic or metal. Thebarrier is placed on the glass surface and in contact adjacent to thewindshield molding. The width of the barrier is selected to eliminatethe higher incidence of damage in the peripheral area; but the width maydiffer between sides, top and bottom, and it may differ in variousvehicles. In one form of the invention, a clear plastic film is adheredto the windshield around its periphery to a selected width from thewindshield molding. The clear plastic film will absorb impact fromflying debris and allow visibility. As an alternative, equivalentprotection can be obtained by a wider molding. Also, the film need notbe clear in all portions of the windshield. The barrier can be installedbefore the windshield is fitted to the vehicle in which case it couldextend to the edge of the glass.

In an alternate preferred embodiment a clear polymeric film is from 6-10mils thick and a preferred thickness is 6-8 mils, most preferably 7 or 8mils. The range of 6-8 mils and the 7 mils thickness being especiallypreferred or bowed windshield portions as thicker films are too stiff.

In another alternate preferred embodiment, the clear film is apolyester. A further preferred embodiment is a clear laminatedmulti-layer, preferably 2 layer polyester film 6-10 mils thick, morepreferably 6-8 mils thick and most preferably 7 or 8 mils. The range of6-8 mils and the 7 or 8 mils thickness being especially preferred onbowed windshield portions.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a front view of a windshield having the inventive filmapplied in an exemplary OEM application.

FIG. 2 shows a front view of a windshield having the inventive filmapplied in an exemplary aftermarket application

DETAILED DESCRIPTION

The invention is a method and means for protecting windshields fromimpacts which would cause damage, most importantly cracks of the kindwhich generally require replacement of the windshield, although in somecases repair is possible. In this invention, when applied to awindshield already installed, the impact absorbing barrier is adhered tothe peripheral areas of the windshield, the sides, top and bottom,adjacent to the molding and extending a selected width into the glassarea. When applied before the windshield is installed, the barrier canextend to the edge of the windshield so that a portion of it is capturedunder the windshield molding. The barrier may be clear or opaque, andmay be of a variety of materials such as plastic film, rubber or metal.

Also the barrier may be constructed by extending the windshieldretaining molding over the glass selected distance.

Plastic film is supplied and used in many thicknesses, configurationsand plastic formulations. Selection of a film thickness and plasticformulation for use in this invention is such as to provide good impactabsorption sufficient to prevent damage from impact which would allow acrack to form. In practice the selected material will prevent anydamage, even a chip because as will be seen a chip in the vulnerableperipheral area commonly leads to an edge crack. In order to minimizedistortion of visibility the film should be as thin as possibleconsistent with achieving the impact absorption goal. This is moreimportant at the sides than at the top and bottom.

Referring to FIG. 1, in the present invention, an automobile windshield1 having a molding 2 around its periphery is the subject of theinvention. A clear plastic film 3 is placed around the periphery insidethe molding. The film 3 should have the selected dimension A. It shouldbe adhered permanently to the windshield by an adhesive layer.Alternatively the film can be adhered in a manner which allows periodicreplacement, for example if the film becomes damaged or worn or losesits clarity.

Therefore, the film 3 will absorb impact and protect the windshield fromrocks and other debris.

Over 90% of windshield long cracks are caused by impacts in theperipheral distance within 4 inches (approximately 10 cm) of the exposedperiphery of the windshield, that is, within a margin measured from themolding to about 4 inches into the glass area. Most of these long cracksare caused by stones, although other flying debris can also cause suchcracks.

The plastic film should be selected from a material that is clear andcrack resistant and will not fog or discolor over time due to sunlightor severe weather conditions.

An exemplary film is 3M Scotchcal™. This is an 8 mils urethane plasticfilm sold by 3M. It has adhesive on one side which will be activated bya solution of 25% isopropyl alcohol and 75% water, then this film can beapplied to a surface for protection. The film could be thicker, forexample up to about 30 mils. A film should be as thick as necessary toabsorb impact but not so thick as to interfere with any function of thewindshield or the wipers.

A preferred method of providing the peripheral protection for OEMapplications is to prepare a one piece four sided clear plastic frame ofthe selected dimensions. It would be shaped to fit along the inside ofthe molding although it could extend under the molding to the glassedge. Most windshields are curved at the sides, some are curved at thetop or bottom. Therefore, the four sided plastic frame is configured tomatch the periphery of the windshield against the molding and extendinginward into the viewing area the selected distance. The frame thereforeshould match the curves to give a uniform distance from the molding.This is seen in FIG. 1. However uniformity is not essential as notedbelow. If the film frame extends under the molding, then curved matchingagainst the molding is irrelevant.

A preferred method of providing the peripheral protection foraftermarket applications uses a roll of film from which desired lengthsare cut off. Then the pieces are laid onto the windshield, marked andcut to the desired configuration. FIG. 2 shows this means and method.The windshield 1 has a molding 2 surrounding it. The plastic frame isformed of four separate pieces, 3A, 3B, 3C and 3D on the left side,right side, top and bottom respectively. Since the individual framepieces are cut from a roll or a strip of selected width the corners 4are to be trimmed off, the ends cut to fit and the inside edges such aspieces 3A and 3B are preferably trimmed to a curvature to match themolding curvature as seen at 5A and 5B. Templates of paper or cardboardmay be made first. Then the film element or elements are prepared withan adhesive and placed on the windshield. The film could also besupplied in wide sheets from which strips are cut having the requisitewidth and shape.

Alternatively the plastic film may be opaque, or the material may berubber or metal.

A 4 inch width of the impact absorbent barrier has been shown to beeffective for over 90% of cracks, other dimensions are defined by theexamples below.

An alternative form of the invention refers to the molding used to helpset and hold the windshield in place. Widening the molding to a selecteddistance over the glass would accomplish the objectives of thisinvention. This could be done when the vehicle is manufactured or whenthe windshield is replaced.

EXAMPLE NO. 1

In this example a total of 235 windshields with long cracks wereobserved in shopping malls in the Colorado Springs, Colo. area inFebruary 1996. These windshields all had long cracks i.e. over 6″ long.Of these, 225 windshields had cracks from impacts up to 5 inches fromthe molding and all were edge cracks. The remaining 10 windshields hadcracks where the impact point was more than 5 inches from the molding.These 10 were scattered all over the windshield middle area. Of these10, some were edge cracks and some were not. The survey did not look atstone damage absent a long crack. It is frequent that an impact in themiddle area does not result in a long crack, and very rare that it wouldresult in an edge crack. For purposes of this survey it was consideredthat 5″ would be the maximum guardable distance from the molding usingthe invention, due to practical limitations. The following data wasobserved:

Percent At 5″ Percent or less Of Crack Location of Total Total 141impact points of the cracks were at or within  63% 60% 1″ (2.5 cm) ofmolding 186 impact points of the cracks were at or within  83% 79% 2″(5.1 cm) of molding 202 impact points of the cracks were at or within 90% 86% 3″ (7.6 cm) of molding 215 impact points of the cracks were ator within  96% 91% 4″ (10.2 cm) of molding 225 impact points of thecracks were at or within 100% 96% 5″ (12.7 cm) of molding 10 additionalimpact points of the cracks were 100% 235 more than 5″ from the molding

NOTE: The above centimeter conversions are not intended to convey anaccuracy level as the measurements were made in inches. Distances areconsidered to have a very large tolerance as great precision is notrelevant. For example the 12.7 cm measurement as considered to be about12 cm.

It is considered that these windshields would most likely be replaced,although the option of repair may be elected by some customers.Therefore if a film width of 5 inches or about 12 cm were employed only10 of 235 windshields would not have been saved.

EXAMPLE II

In this example, 236 windshields with long cracks were observed at ashopping mall in Colorado Springs, Colo. in March 1996. Of the total,203 damaged windshields with long cracks which were edge cracks fromimpacts within 6 cm of the edge.

Of the thirty three cracks from impacts beyond 6 cm from the molding,about half went to the edge. Of the thirty three, only three were fromimpacts in the distance between 6 cm and 12 cm from the molding. Also415 chips were found which were more than 6 cm from the edge, withoutany crack. Also there were 23 chips within 6 cm which had not yetcracked, although it is presumed they would crack shortly they are notcounted as cracks in this survey.

This data can be summarized as follows:

TABLE 2 Percent of Percent Total at of Overall 6 cm or less Total 74 ofthe impact points were at or within 36% 31% 1 cm of molding 137 of theimpact points were at or within 67% 58% 2 cm of molding 163 of theimpact points were at or within 80% 69% 3 cm of molding 184 of theimpact points were at or within 91% 78% 4 cm of molding 191 of theimpact points were at or within 94% 81% 5 cm of molding 203 of theimpact points were at or within 100%  86% 6 cm of molding 33 of theimpact points were beyond 100%  236 6 cm from the molding

The data from this survey summarized by impact location for 203 impactswithin 6 cm are:

Top—45 total windshields chipped at the top, all had cracked

16 were chipped at 1(0.39″) centimeter from the molding.

9 were chipped at 1.5 centimeters from the molding.

5 were chipped at 2 centimeters from the molding.

1 was chipped at 2.5 centimeters from the molding.

6 were chipped at 3 centimeters from the molding.

3 were chipped at 3.5 centimeters from the molding.

3 were chipped at 4 centimeters from the molding.

2 were chipped at 5.5 centimeters from the molding.

45

Sides—66 total windshields chipped at the sides, all had cracked

28 were chipped at 1 centimeter from the molding.

7 were chipped at 1.5 centimeters from the molding.

12 were chipped at 2 centimeters from the molding.

4 were chipped at 2.5 centimeters from the molding.

7 were chipped at 3 centimeters from the molding.

1 was chipped at 4 centimeters from the molding.

1 was chipped at 4.5 centimeters from the molding.

1 was chipped at 5 centimeters from the molding.

2 were chipped at 5.5 centimeters from the molding.

3 were chipped at 6 centimeters from the molding.

66

Bottom—96 total windshields chipped at bottom, and had cracked

30 were chipped at 1 centimeter from the molding.

14 were chipped at 1.5 centimeters from the molding.

16 were chipped at 2 centimeters from the molding.

5 were chipped at 2.5 centimeters from the molding.

3 were chipped at 3 centimeters from the molding.

3 were chipped at 3.5 centimeters from the molding.

11 were chipped at 4 centimeters from the molding.

3 were chipped at 4.5 centimeters from the molding.

2 were chipped at 5 centimeters from the molding.

1 was chipped at 5.5 centimeters from the molding.

4 were chipped at 6 centimeters from the molding.

92

A number of chips which had not cracked were seen beyond 6 cm from theedge these are considered windshields that are not destroyed, as chipspast 6 cm rarely crack. Also, 23 additional chips were observed within 6cm of the molding, which had not cracked. Although these were notcounted as cracks it is known that any chip from 6 cm or less willnearly always eventually produce an edge crack while chips beyond 6 cmrarely produce an edge crack.

The rules adapted by the Ultra Bond Corporation for its repair methods,establish that most cracks over 18″ long should not be repaired becauseof dirt accumulation in such cracks. Thirty two of the 236 edge crackswere 18″ or under. Under this rule, 32 of the 236 cracks were deemedrepairable. The balance, 204, would not be considered repairable.However most cracked windshields are replaced anyway.

The data conclusion is that a 6 cm wide impact resistant film would haveprevented 86% of the edge cracks.

EXAMPLE III

These data were observed over a period of time at a windshieldreplacement and repair shop in Colorado Springs, Colo. A total of 80windshields were surveyed which had long cracks. Many chips (the impactpoint) were observed in the “frit” at the edge of the windshield. Thisis the black border near the edge of some windshields.

TABLE 1 Cumulative Data Percent of Percent of Total at Owned 6 cm orLess Total 36 of the impact points were at or within 52% 45% 1 cm ofmolding 54 of the impact points were at or within 78% 67% 2 cm ofmolding 60 of the impact points were at or within 87% 75% 3 cm ofmolding 36 of the impact points were at or within 52% 45% 1 cm ofmolding 54 of the impact points were at or within 78% 67% 2 cm ofmolding 60 of the impact points were at or within 87% 75% 3 cm ofmolding 65 of the impact points were at or within 94% 81% 4 cm ofmolding 68 of the impact points were at or within 99% 85% 5 cm ofmolding 69 of the impact points were at or within 100%  86% 69 6 cm ofmolding 11 of the impact points were beyond 100%  80 6 cm from themolding

Also in this survey distribution data for the 69 impacts were taken.These are:

16 were chipped at the top

1 at 0.5 cm

11 at 1 cm

3 at 2 cm

1 at 5 cm

22 were chipped on the sides

1 at 0.5 cm

10 at 1 cm

7 at 2 cm

1 at 2.5 cm

3 at 4 cm

31 were chipped on the bottom

1 at 0.5 cm

12 at 1 cm

2 at 1.5 cm

6 at 2 cm

5 at 3 cm

2 at 4 cm

1 at 4.5 cm

1 at 5 cm

1 at 6 cm

EXAMPLE IV

Forty-three windshields having edge cracks over six inches long werestudied. Fourteen were cracked near the bottom. Of these, the chiplocation was noted as follows:

Number Distance of of Impact From Percent of Cumulative Observed BottomMolding Total Total 7 2.0 cm (0.79″) 50% 50% 3 1.0 cm (0.39″) 22% 77% 24.5 cm (1.77″) 14% 86% 2 12.0 cm (4.72″)  14% 100%  14 

The balance, 29, were elsewhere but close to the top and sides. That is,32% of the cracks were from damage near the bottom versus the sides andtop.

EXAMPLE V

A random survey of 200 repaired cracks from a windshield repair shop inRiverside, Calfi. showed that 3 out of 200 long cracks were floaters(did not extend to the edge) and the balance, 197 were edge cracks.

Coupled with the data in Examples I-IV it is concluded that theoverwhelming majority of long cracks are from impacts near the edge.Nearly all of these would result in windshield replacement, the edgecrack is the cause of over 90% of windshield replacements. The presentinvention would nearly eliminate the need for windshield replacement orlong crack repair.

So-called stone damage, that is damage that does not have a long crackfrequently appears as a bullseye, star break or combination break.Sometimes stone damage results in later evolution of a long crack.However in the vulnerable peripheral areas, an impact is most frequentlyseen as a small surface chip, absent any bullseye or starring but with acrack running through the impact point to the edge of the glass. A chip,which defines the point of impact, when near the edge is usually justpin head size, but on some occasions it is a star or bullseye. In suchcases, either instantly or very soon (minutes or at most a few hours)after impact a long crack appears running through the impact point tothe edge of the glass (called an edge crack). Exceptions are extremelyrare. Cracks from the top and bottom often proceed vertically for ashort distance, then turn horizontally. Virtually all cracks formed froman impact in the vulnerable area extend to the glass edge. Cracks thatextend to the glass edge open wider than cracks which don't extend tothe glass edge and travel faster.

The peripheral area of the windshield defines a vulnerable area morespecifically defined by the above data. It is believed that thisvulnerability derives from the windshield being under greater stress andstrain in the vulnerable area from being attached to the vehicle and theslight bow shape. Also, near the bottom there is increased strain fromuse of defrosters/heaters directed at the lower portion of thewindshield.

For practical reasons it is considered that about 12 cm is the maximumguardable width of the periphery. This is due to concerns respectinginterference by or damage to the barrier from windshield wiper operationand interference with visibility. Also wear and tear on wiper blades isa concern. This will vary among vehicle configurations. Also, it isappreciated that visibility concerns allow a wider film at the top andbottom. Also, in some vehicles the hood line is above the molding at thebottom of the windshield. That is, the windshield and the molding extendbelow the hood line.

A survey of windshield moldings disclosed the following data:

Vehicle Molding Width and Data 1988 to 1995 Chevy Full Size P.U. ⅜″ Nags#1026-121 1986 to 1995 Ford Taurus ⅜″ Nags #1097 1990 to 1995 FordExplorer ⅜″ Nags #1087 1985 to 1994 Subaru Loyale ⅛″ FCW #499 1982 to1990 Chevy Celebrity ¼″ WIC #14 1993 to 1995 Jeep Grand Cherokee ¼″ WIC#14 1989 to 1995 Toyota P.U. ⅜″ Nags #598 1987 to 1995 Chrysler Leberon½″ Nags #10 1993 to 1995 Chrysler Concord ⅜″ Nags #118

Another survey of windshield moldings disclosed the following data:

Measurement Vehicle of Molding 1994 Ford Explorer 2 cm 1992 MitsubishiDiamante 1½ cm 1982 Jeep Eagle 2 cm Geo Prizm less than ½ cm Saturn 1½cm Toyota 4 Runner 1½ cm Dodge Dynasty 1½ cm Ford Bronco 2 cm ChevyBlazer 1 cm Buick Century 1 cm Dodge Caravan 1 cm Toyota Startlet 2 cmGMC Surburban 2 cm Ford Mustang 2 cm Chevy Corsica 1½ cm Toyota Celica 1cm Jeep Grand Wagoneer 1½ cm Pontiac Grand Prix 1 cm Honda Civic 1 cmSubaru Wagon 1 cm Nissan Maxima 1 cm Ford Tempo 1 cm Audi 5000 1 cmBuick Park Avenue 1 cm Honda Sedan ½ cm Honda Civic VX ½ cm PontiacTransport 1 cm Cadillac 2 cm Honda Accord EX 1 cm 1994 Ford Taurus 1 cm

Therefore, if a barrier is to be provided by an extended molding, itshould be preferably at least about 4 cm over the glass or preferably atleast about 5 cm over the glass. The molding should preferably extend toa limit about the same distance as demonstrated by the foregoingexamples.

It is appreciated that application of a shock absorbent film or otherbarrier on the bottom of the windshield will have to be different fromthat at the top and sides in many vehicles. This is because of thepeculiar construction of some vehicles at and adjacent the bottom of thewindshield. In some such cases the bottom of the windshield is under thelevel of the hood, and sometimes has as much as two inches of protectionfrom the hood. The molding will be below the hood line. In such casesexposure of the windshield to damage begins at the level of the hood.That is, below the hood, it is not expected to see damage. Thus, thevulnerable area is defined as beginning from the hood line, where thewindshield extends below the hood line. Also, some vehicles have a widermolding on the bottom and it may have a complex shape. Therefore it isuseful to define an effective border for the bottom of the windshieldwhich is either the molding inner edge or the hood line, whichever ishigher. For the top and sides, the molding inner edge is the border. The1986 Cadillac Sedan DeVille, for example, has a 6 cm. metal molding onthe bottom and a 1 cm conventional molding on the top and sides. Also,when viewing the bottom of the windshield from the front, level with thehood, this 6 cm molding is not seen, that is, it does not cover any ofthe exposed glass, the entire 6 cm molding is beneath the level of thehood (note the 6 cm molding covers only about 2 cm of glass).

Moldings of such greater width apparently are only used on the bottom.Many vehicles have different molding on the bottom than on the top andsides. The impact protective barrier of this invention, can be wider onthe bottom than at the top and sides because there is less potentialinterference with visibility, and in some cases it will extend below thehood. The bottom protective barrier will have to extend upward beyondthe level of the hood. The top also allows greater width due to lesspotential interference with visibility.

Whether the protective barrier is incorporated into the OEM orreplacement molding, the foregoing considerations should be appreciated.Many vehicles have a black “frit” which extends as much as 5″ on somevehicles, commonly about 1″-2″ from the molding. If the impact absorbentbarrier is limited to the frit then visibility would not necessarily beinterfered with and therefore clarity if of less concern. An opaquebarrier would be more acceptable.

In a preferred embodiment the film is a clear polyester. It can be asingle-ply of film. A further preference is that the polyester film be alaminated multi-ply, more preferably 2-ply. Such films have a preferredthickness range of 6-10 mils, more preferably 6-8 mils, the mostpreferred thickness being 7 or 8 mils. The range of 6-8 mils thick ispreferred when used with bowed windshield surfaces. The term bowedrefers to curvature in the planar surface or body of the windshield,this term being used to distinguish over the term curved as related tothe peripheral lines described above, as shown in FIGS. 1 & 2. Sometimesbowing is a compound curvature, the windshield being bowed bothhorizontally and vertically. In the case of bowed surfaces, the film maybe too stiff. Thus, it has been found that the thickness at 10 mils maybe too stiff when applied to bowed surfaces while the 6-8 mil range isnot too stiff. The most preferred thickness is 7 and 8 mils. Thesethickness designations refer to the nominal measurements provided bymanufacturers of plastic film.

Polyester films exemplary of the above description and having been usedsuccessfully are made by MADICO, Inc., Woburn, Mass. as its productdesignations LCL-600-XSR and LCL-800-XSR and a 7 mil film sold by thatcompany.

Further, the preferred film width is 3 inches for the top and sides and4 inches for the bottom; this dimension being derived from a broad rangeof applications and experience to reach the best average for allapplications. Also, special issues at the bottom are appreciated, thatmore impacts and therefore more edge cracks are seen at the bottom thanat either the sides or top. Stone breaks that become edge cracks aremore frequent at the bottom. Also, the bottom can tolerate a greaterwidth because visibility is not an issue until higher on the windshield.And, finally, even if the windshield is below the hood line, 4 inchesworks well because the stresses on the windshield decrease as thedistance from the edge increases. This is significant because it is notthe distance per se from the edge which causes an edge crack, but ratherthe increased stress nearer to the edge.

In another aspect of the invention, universal molding is provided whichhas a selected width over the top of the glass. Such universal moldingwould be configured in its cross section according to the known shapeson the inside of the windshield, at the edge and at the outside of thewindshield but in the latter case, that is over the outside of thewindshield it will extend further. Selected universal moldings wouldpreferably be made at 2 inches, 2½ inches and 3 inch widths. With theseuniversal moldings available a glass replacement shop would select thebest universal molding to fit the vehicle windshield so that it canreplace not just the glass, but also provide the impact absorptionprotection of the invention by reason of the outside extended portion ofthe molding.

In another aspect of the invention, the invention can be practiced byapplying a film or molding which an extended outside portion adhered tothe windshield when the windshield is made. In this way a windshieldreplacement shop has supplied to it a windshield already combined withthe impact absorbing film or coating.

In other aspects of the invention the impact barrier portion is a filmwhich incorporates a frit. The frit is a black paint applied to thewindshield to block sun rays from damaging the urethane adhesive whichis used to adhere the windshield to the molding. In this aspect, in oneexample, a primary film of polycarbonate was assembled with another filmlaminated to it which was of black polyester. The laminate was adheredto the windshield with the black polyester film against the outersurface of the windshield, the film of polycarbonate being exterior.

This aspect can also be practiced with a single film on the windshieldwhich is darkened or black, to prevent damage to the urethane adhesiveby filtering out the damaging sunlight. The coloring material is of atype that will prevent sunlight which is degrading to urethane frompassing through.

In this way the film can accomplish the dual function of impact barrierand protection of the urethane from sunlight damage.

In another aspect of the invention, especially useful for after marketapplication, a kit is prepared. The kit is customized for a particularcar, or cars. It is common in the industry that a windshield size andshape may be used on several vehicles. A set of kits can be defined fora large Ace number of vehicles on the road. The kit has as its primaryelement four pieces of impact absorbing barrier material pre-shaped tofit the two sides, top and bottom of the windshield. Alternatively, thekit may only provide the top and sides, the bottom, the sides, or infact any combination of the two sides, top and the bottom. Also, asdiscussed, these need not all be the same width, although they may be.Nor need they be of the same material. For example, the sides and topmay be a polycarbonate film, and the bottom a metal strip. The sides andtop may incorporate the dual purpose film described above by beingdarkened or black to protect urethane from sunlight damage while thebottom is a metal strip, which would also have the urethane protectingeffect.

The impact absorbing barrier elements of the kit are conveniently madefrom a roll of film and cut to match the shape of the windshield to abutthe molding and each other at their ends the cutting can be done by anyconvenient method, laser cutting having proven to be preferred. Theimpact absorbing barrier elements will have an adhesive layer on theside intended to lay on the windshield. This adhesive as described aboveis preferably of the activateable type. Therefore, the kit also includesa container of activating fluid for the adhesive. Finally, a usefulelement of the kit is a pressing bar having a rigid or semi-rigid edgesuch as a squeegee to smoothly press the film in place. Also, a barsimilar to those used for wallpaper application could be used.

The kit as described is used to apply the film to a windshield alreadyin place, with a molding around its edge. But the kits can also be madein a series to allow application of the film on a windshield prior toits installation on the vehicle. In this case the impact barriermaterial is cut to be co-extensive to the edge of the windshield. Oninstallation, the impact barrier will extend under the molding.

In effect all the variations of shape, size, material, clear, opaque,darkened or black barriers can be adapted to the kit.

The kit assembly is particularly helpful to enable consumers toconveniently use the invention, and is also useful for professionalwindshield installers who are able to work fast and accurately withoutneed for special skills such as cutting the barrier to shape, nor tohave an inventory of raw materials.

The foregoing discussion refers to use of pre-formed film material suchas the preferred polycarbonate film to provide the impact resistantbarrier. It is also an aspect of the invention that the impact resistantbarrier can be formed on the windshield by application of a material ina fluid condition, laid down for example by spraying or rolling tocreate a film or coating which forms after being applied such as by UV,heat, or other curing process. Coloring material can be mixed into thefluid to provide the protection for urethane from degradation. It isconsidered that all the variations of the invention implemented by apreformed film could be implemented in this manner.

Although particular embodiments of the invention have been described andillustrated herein, it is recognized that modifications and variationsmay readily occur to those skilled in the art, and consequently it isintended that the claims be interpreted to cover such modifications andequivalents.

What is claimed is:
 1. A method of guarding a vehicle windshield againstdamage from inpacts comprising; forming a coating film of selected widthupon at least a portion of the periphery of the windshield from impactresistive material.
 2. The method of claim 1 wherein said impactresistive material is a polycarbonate.
 3. A method of providing avehicle windshield exterior surface with a barrier of impact protectingmaterial for protection against damage from impacts comprising; formingfrom impact resistance material a coating of selected width uponselected portions of the outside periphery of the windshield; saidcoating being formed by depositing said material upon the outsidesurface of the selected portions of the outside periphery of thewindshield in curable fluid form and curing said material to form a filmof said impact resistive material.
 4. The method of claim 3 wherein saidat least a portion of the periphery of the windshield is selected fromone or more of; a. the sides of the windshield; b. the top of thewindshield; c. the bottom of the windshield.
 5. The method of claim 1wherein said coating film is formed on said windshield while it is notinstalled in a vehicle and said coating extends to the edge of thewindshield.
 6. The method of claim 3 wherein said material had mixedinto it a coloring ingredient which is blocking of sunlight which causesdegeneration of urethane.
 7. The method of claim 3 wherein said impactresistive material is a polycarbonate.